The invention relates to gripping pliers for grasping and holding an object, having at least two gripper jaws, movable in reference to each others, and having a drive for an opening and closing movement of the gripping jaws, with at least one of the gripping jaws comprising several fingers, arranged side-by-side to each other, each individually adjustable approximately in the opening and closing direction against a restoring force.
Such gripping pliers are known in numerous embodiments and are used to move objects from one place to another. For example, tooth brushes can be moved from a processing device or a brush storage area to a processing device arranged downstream. The range of application of such gripping pliers is not limited to the production of brushes, however.
The object to be grasped is here held in a clamping fashion between opposite gripping jaws. Here, it is problematic that depending on its design the object may lean laterally during the gripping process and thus perhaps cannot be put down in the desired position. In order to solve this problem, two gripping pliers or one set of gripping pliers with two pairs of gripping jaws can be used, tightly holding the object at several positions. This is subject to high costs, though, and due to the higher weight of twice the number of gripping jaws to be moved the operating speed is reduced.
Alternatively, gripping pliers may be used comprising one gripping jaw with a gripping finger and an opposite gripping jaw with two gripping fingers. Using such a three-point system an object may be held in a better fashion, however here too, there is the risk that the object, for example a tooth brush with a curved brush body, rotates within the gripping pliers, which in turn aggravates the placement of the object, for example in a stacking magazine.
In order to address the problem that the object may become damaged when the gripping jaws engage it with excessive force, it is already known in practice for gripping pliers to have gripping jaws comprising several fingers, each of them individually adjustable against a restoring force.
Particularly in profiled objects, there is the problem in simpler gripping pliers that the object is impinged by a gripping jaw with an insufficient holding force at one point and at some other points no contact occurs between the object and the gripping jaw. When increasing the holding force the gripping jaw may be made to approach the sections of the object initially not grasped. However, here the pressure upon those sections of the object increases, which already were in contact with the gripping jaws at an earlier time. In this manner, pressure points or damages can develop at the object. Such pressure impingements of the object are to be avoided, in particular when using gripping pliers in food processing.
By the further developed gripping pliers having individually adjustable fingers, the gripping jaws for grasping an object can be made approaching each other, with in case of a profiled object, for example a the body of a tooth brush, the individual fingers can form to the object according to its external contour and with increasing holding force be deflected individually against the restoring force such that the object, on the one side, is held at each point within the grasping range, on the other side, there is no point at which an excessive pressure acts upon the object such that it could be damaged or that pressure points could form. The individual fingers can here be deflected to a different extent according to the contour of the object. This allows a secure and reliable holding of an object in a defined position having a holding force, which is sufficient to hold the object without damaging it thereby.
The gripping pliers known, and comprising individually adjustable fingers, are expensive, though, in their production because each finger must be mounted individually. This renders their production more expensive. Additionally, the gripping jaws comprise a relatively high weight by the required connection elements for an adjustable mounting of the fingers, which limits the maximally possible processing speed of the gripping pliers.